The 37-year-old former Spice Girl band member, who previously worked on Australian version of 'The X Factor', is said to have signed a deal to join the judging panel.

"Simon loves trying people out on his shows, Mel's already been a judge on 'X Factor' Australia and it's too far for her to keep taking the kids," a source told the dailymail.co.uk.

"She did want to do 'X Factor' UK, but Simon really wanted her to do 'America's Got Talent'.

She's outspoken and never afraid to speak her mind, she makes for good TV. NBC execs will be watching through their eyes - let's hope they won't be using the delay button on live TV," the source added.